In the recent years, there has been some development in developing core body temperature sensors. A heat flux temperature sensor is an example of such a core body temperature sensor, but the measuring is based on so-called zero heat flux principle, but this principle is used in the “low power core body temperature monitoring” for continuous temperature monitoring of patients. According to this principle the core body temperature is measured by placing the sensor on the skin of e.g. the forehead of the patient. An accurate temperature measurement requires that the sensor is flexible so that it follows that skin surface so as to ensure that there are no air gaps between the skin and sensor, which otherwise can have adverse effect on the measurement accuracy.
Although the prior art heat flux temperature sensors are somewhat flexible, they are suitable for high acuity applications, e.g. during surgery where the sensor monitors the core body temperature during the surgery and where the patient is not moving.
However, for applications where the skin is actually moving more, e.g. for monitoring temperature of newborns, or more general use (e.g. outside the hospital) their use is somewhat limited due to the lack of flexibility needed to follow the skin surface. Also the prior art sensors are obtrusive, either for newborns requiring an adhesive on the skin, or for non-high acuity applications being visible on the patient's forehead, changing the appearance of the patient.